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1 /*
2  * Copyright 2015-2020 The OpenSSL Project Authors. All Rights Reserved.
3  * Copyright 2004-2014, Akamai Technologies. All Rights Reserved.
4  *
5  * Licensed under the OpenSSL license (the "License").  You may not use
6  * this file except in compliance with the License.  You can obtain a copy
7  * in the file LICENSE in the source distribution or at
8  * https://www.openssl.org/source/license.html
9  */
10 
11 /*
12  * This file is in two halves. The first half implements the public API
13  * to be used by external consumers, and to be used by OpenSSL to store
14  * data in a "secure arena." The second half implements the secure arena.
15  * For details on that implementation, see below (look for uppercase
16  * "SECURE HEAP IMPLEMENTATION").
17  */
18 #include "e_os.h"
19 #include <openssl/crypto.h>
20 
21 #include <string.h>
22 
23 /* e_os.h defines OPENSSL_SECURE_MEMORY if secure memory can be implemented */
24 #ifdef OPENSSL_SECURE_MEMORY
25 # include <stdlib.h>
26 # include <assert.h>
27 # include <unistd.h>
28 # include <sys/types.h>
29 # include <sys/mman.h>
30 # if defined(OPENSSL_SYS_LINUX)
31 #  include <sys/syscall.h>
32 #  if defined(SYS_mlock2)
33 #   include <linux/mman.h>
34 #   include <errno.h>
35 #  endif
36 # endif
37 # if defined(__FreeBSD__)
38 #  define MADV_DONTDUMP MADV_NOCORE
39 # endif
40 # if !defined(MAP_CONCEAL)
41 #  define MAP_CONCEAL 0
42 # endif
43 # include <sys/param.h>
44 # include <sys/stat.h>
45 # include <fcntl.h>
46 #endif
47 
48 #define CLEAR(p, s) OPENSSL_cleanse(p, s)
49 #ifndef PAGE_SIZE
50 # define PAGE_SIZE    4096
51 #endif
52 #if !defined(MAP_ANON) && defined(MAP_ANONYMOUS)
53 # define MAP_ANON MAP_ANONYMOUS
54 #endif
55 
56 #ifdef OPENSSL_SECURE_MEMORY
57 static size_t secure_mem_used;
58 
59 static int secure_mem_initialized;
60 
61 static CRYPTO_RWLOCK *sec_malloc_lock = NULL;
62 
63 /*
64  * These are the functions that must be implemented by a secure heap (sh).
65  */
66 static int sh_init(size_t size, int minsize);
67 static void *sh_malloc(size_t size);
68 static void sh_free(void *ptr);
69 static void sh_done(void);
70 static size_t sh_actual_size(char *ptr);
71 static int sh_allocated(const char *ptr);
72 #endif
73 
CRYPTO_secure_malloc_init(size_t size,int minsize)74 int CRYPTO_secure_malloc_init(size_t size, int minsize)
75 {
76 #ifdef OPENSSL_SECURE_MEMORY
77     int ret = 0;
78 
79     if (!secure_mem_initialized) {
80         sec_malloc_lock = CRYPTO_THREAD_lock_new();
81         if (sec_malloc_lock == NULL)
82             return 0;
83         if ((ret = sh_init(size, minsize)) != 0) {
84             secure_mem_initialized = 1;
85         } else {
86             CRYPTO_THREAD_lock_free(sec_malloc_lock);
87             sec_malloc_lock = NULL;
88         }
89     }
90 
91     return ret;
92 #else
93     return 0;
94 #endif /* OPENSSL_SECURE_MEMORY */
95 }
96 
CRYPTO_secure_malloc_done(void)97 int CRYPTO_secure_malloc_done(void)
98 {
99 #ifdef OPENSSL_SECURE_MEMORY
100     if (secure_mem_used == 0) {
101         sh_done();
102         secure_mem_initialized = 0;
103         CRYPTO_THREAD_lock_free(sec_malloc_lock);
104         sec_malloc_lock = NULL;
105         return 1;
106     }
107 #endif /* OPENSSL_SECURE_MEMORY */
108     return 0;
109 }
110 
CRYPTO_secure_malloc_initialized(void)111 int CRYPTO_secure_malloc_initialized(void)
112 {
113 #ifdef OPENSSL_SECURE_MEMORY
114     return secure_mem_initialized;
115 #else
116     return 0;
117 #endif /* OPENSSL_SECURE_MEMORY */
118 }
119 
CRYPTO_secure_malloc(size_t num,const char * file,int line)120 void *CRYPTO_secure_malloc(size_t num, const char *file, int line)
121 {
122 #ifdef OPENSSL_SECURE_MEMORY
123     void *ret;
124     size_t actual_size;
125 
126     if (!secure_mem_initialized) {
127         return CRYPTO_malloc(num, file, line);
128     }
129     CRYPTO_THREAD_write_lock(sec_malloc_lock);
130     ret = sh_malloc(num);
131     actual_size = ret ? sh_actual_size(ret) : 0;
132     secure_mem_used += actual_size;
133     CRYPTO_THREAD_unlock(sec_malloc_lock);
134     return ret;
135 #else
136     return CRYPTO_malloc(num, file, line);
137 #endif /* OPENSSL_SECURE_MEMORY */
138 }
139 
CRYPTO_secure_zalloc(size_t num,const char * file,int line)140 void *CRYPTO_secure_zalloc(size_t num, const char *file, int line)
141 {
142 #ifdef OPENSSL_SECURE_MEMORY
143     if (secure_mem_initialized)
144         /* CRYPTO_secure_malloc() zeroes allocations when it is implemented */
145         return CRYPTO_secure_malloc(num, file, line);
146 #endif
147     return CRYPTO_zalloc(num, file, line);
148 }
149 
CRYPTO_secure_free(void * ptr,const char * file,int line)150 void CRYPTO_secure_free(void *ptr, const char *file, int line)
151 {
152 #ifdef OPENSSL_SECURE_MEMORY
153     size_t actual_size;
154 
155     if (ptr == NULL)
156         return;
157     if (!CRYPTO_secure_allocated(ptr)) {
158         CRYPTO_free(ptr, file, line);
159         return;
160     }
161     CRYPTO_THREAD_write_lock(sec_malloc_lock);
162     actual_size = sh_actual_size(ptr);
163     CLEAR(ptr, actual_size);
164     secure_mem_used -= actual_size;
165     sh_free(ptr);
166     CRYPTO_THREAD_unlock(sec_malloc_lock);
167 #else
168     CRYPTO_free(ptr, file, line);
169 #endif /* OPENSSL_SECURE_MEMORY */
170 }
171 
CRYPTO_secure_clear_free(void * ptr,size_t num,const char * file,int line)172 void CRYPTO_secure_clear_free(void *ptr, size_t num,
173                               const char *file, int line)
174 {
175 #ifdef OPENSSL_SECURE_MEMORY
176     size_t actual_size;
177 
178     if (ptr == NULL)
179         return;
180     if (!CRYPTO_secure_allocated(ptr)) {
181         OPENSSL_cleanse(ptr, num);
182         CRYPTO_free(ptr, file, line);
183         return;
184     }
185     CRYPTO_THREAD_write_lock(sec_malloc_lock);
186     actual_size = sh_actual_size(ptr);
187     CLEAR(ptr, actual_size);
188     secure_mem_used -= actual_size;
189     sh_free(ptr);
190     CRYPTO_THREAD_unlock(sec_malloc_lock);
191 #else
192     if (ptr == NULL)
193         return;
194     OPENSSL_cleanse(ptr, num);
195     CRYPTO_free(ptr, file, line);
196 #endif /* OPENSSL_SECURE_MEMORY */
197 }
198 
CRYPTO_secure_allocated(const void * ptr)199 int CRYPTO_secure_allocated(const void *ptr)
200 {
201 #ifdef OPENSSL_SECURE_MEMORY
202     int ret;
203 
204     if (!secure_mem_initialized)
205         return 0;
206     CRYPTO_THREAD_write_lock(sec_malloc_lock);
207     ret = sh_allocated(ptr);
208     CRYPTO_THREAD_unlock(sec_malloc_lock);
209     return ret;
210 #else
211     return 0;
212 #endif /* OPENSSL_SECURE_MEMORY */
213 }
214 
CRYPTO_secure_used(void)215 size_t CRYPTO_secure_used(void)
216 {
217 #ifdef OPENSSL_SECURE_MEMORY
218     return secure_mem_used;
219 #else
220     return 0;
221 #endif /* OPENSSL_SECURE_MEMORY */
222 }
223 
CRYPTO_secure_actual_size(void * ptr)224 size_t CRYPTO_secure_actual_size(void *ptr)
225 {
226 #ifdef OPENSSL_SECURE_MEMORY
227     size_t actual_size;
228 
229     CRYPTO_THREAD_write_lock(sec_malloc_lock);
230     actual_size = sh_actual_size(ptr);
231     CRYPTO_THREAD_unlock(sec_malloc_lock);
232     return actual_size;
233 #else
234     return 0;
235 #endif
236 }
237 /* END OF PAGE ...
238 
239    ... START OF PAGE */
240 
241 /*
242  * SECURE HEAP IMPLEMENTATION
243  */
244 #ifdef OPENSSL_SECURE_MEMORY
245 
246 
247 /*
248  * The implementation provided here uses a fixed-sized mmap() heap,
249  * which is locked into memory, not written to core files, and protected
250  * on either side by an unmapped page, which will catch pointer overruns
251  * (or underruns) and an attempt to read data out of the secure heap.
252  * Free'd memory is zero'd or otherwise cleansed.
253  *
254  * This is a pretty standard buddy allocator.  We keep areas in a multiple
255  * of "sh.minsize" units.  The freelist and bitmaps are kept separately,
256  * so all (and only) data is kept in the mmap'd heap.
257  *
258  * This code assumes eight-bit bytes.  The numbers 3 and 7 are all over the
259  * place.
260  */
261 
262 #define ONE ((size_t)1)
263 
264 # define TESTBIT(t, b)  (t[(b) >> 3] &  (ONE << ((b) & 7)))
265 # define SETBIT(t, b)   (t[(b) >> 3] |= (ONE << ((b) & 7)))
266 # define CLEARBIT(t, b) (t[(b) >> 3] &= (0xFF & ~(ONE << ((b) & 7))))
267 
268 #define WITHIN_ARENA(p) \
269     ((char*)(p) >= sh.arena && (char*)(p) < &sh.arena[sh.arena_size])
270 #define WITHIN_FREELIST(p) \
271     ((char*)(p) >= (char*)sh.freelist && (char*)(p) < (char*)&sh.freelist[sh.freelist_size])
272 
273 
274 typedef struct sh_list_st
275 {
276     struct sh_list_st *next;
277     struct sh_list_st **p_next;
278 } SH_LIST;
279 
280 typedef struct sh_st
281 {
282     char* map_result;
283     size_t map_size;
284     char *arena;
285     size_t arena_size;
286     char **freelist;
287     ossl_ssize_t freelist_size;
288     size_t minsize;
289     unsigned char *bittable;
290     unsigned char *bitmalloc;
291     size_t bittable_size; /* size in bits */
292 } SH;
293 
294 static SH sh;
295 
sh_getlist(char * ptr)296 static size_t sh_getlist(char *ptr)
297 {
298     ossl_ssize_t list = sh.freelist_size - 1;
299     size_t bit = (sh.arena_size + ptr - sh.arena) / sh.minsize;
300 
301     for (; bit; bit >>= 1, list--) {
302         if (TESTBIT(sh.bittable, bit))
303             break;
304         OPENSSL_assert((bit & 1) == 0);
305     }
306 
307     return list;
308 }
309 
310 
sh_testbit(char * ptr,int list,unsigned char * table)311 static int sh_testbit(char *ptr, int list, unsigned char *table)
312 {
313     size_t bit;
314 
315     OPENSSL_assert(list >= 0 && list < sh.freelist_size);
316     OPENSSL_assert(((ptr - sh.arena) & ((sh.arena_size >> list) - 1)) == 0);
317     bit = (ONE << list) + ((ptr - sh.arena) / (sh.arena_size >> list));
318     OPENSSL_assert(bit > 0 && bit < sh.bittable_size);
319     return TESTBIT(table, bit);
320 }
321 
sh_clearbit(char * ptr,int list,unsigned char * table)322 static void sh_clearbit(char *ptr, int list, unsigned char *table)
323 {
324     size_t bit;
325 
326     OPENSSL_assert(list >= 0 && list < sh.freelist_size);
327     OPENSSL_assert(((ptr - sh.arena) & ((sh.arena_size >> list) - 1)) == 0);
328     bit = (ONE << list) + ((ptr - sh.arena) / (sh.arena_size >> list));
329     OPENSSL_assert(bit > 0 && bit < sh.bittable_size);
330     OPENSSL_assert(TESTBIT(table, bit));
331     CLEARBIT(table, bit);
332 }
333 
sh_setbit(char * ptr,int list,unsigned char * table)334 static void sh_setbit(char *ptr, int list, unsigned char *table)
335 {
336     size_t bit;
337 
338     OPENSSL_assert(list >= 0 && list < sh.freelist_size);
339     OPENSSL_assert(((ptr - sh.arena) & ((sh.arena_size >> list) - 1)) == 0);
340     bit = (ONE << list) + ((ptr - sh.arena) / (sh.arena_size >> list));
341     OPENSSL_assert(bit > 0 && bit < sh.bittable_size);
342     OPENSSL_assert(!TESTBIT(table, bit));
343     SETBIT(table, bit);
344 }
345 
sh_add_to_list(char ** list,char * ptr)346 static void sh_add_to_list(char **list, char *ptr)
347 {
348     SH_LIST *temp;
349 
350     OPENSSL_assert(WITHIN_FREELIST(list));
351     OPENSSL_assert(WITHIN_ARENA(ptr));
352 
353     temp = (SH_LIST *)ptr;
354     temp->next = *(SH_LIST **)list;
355     OPENSSL_assert(temp->next == NULL || WITHIN_ARENA(temp->next));
356     temp->p_next = (SH_LIST **)list;
357 
358     if (temp->next != NULL) {
359         OPENSSL_assert((char **)temp->next->p_next == list);
360         temp->next->p_next = &(temp->next);
361     }
362 
363     *list = ptr;
364 }
365 
sh_remove_from_list(char * ptr)366 static void sh_remove_from_list(char *ptr)
367 {
368     SH_LIST *temp, *temp2;
369 
370     temp = (SH_LIST *)ptr;
371     if (temp->next != NULL)
372         temp->next->p_next = temp->p_next;
373     *temp->p_next = temp->next;
374     if (temp->next == NULL)
375         return;
376 
377     temp2 = temp->next;
378     OPENSSL_assert(WITHIN_FREELIST(temp2->p_next) || WITHIN_ARENA(temp2->p_next));
379 }
380 
381 
sh_init(size_t size,int minsize)382 static int sh_init(size_t size, int minsize)
383 {
384     int ret;
385     size_t i;
386     size_t pgsize;
387     size_t aligned;
388 
389     memset(&sh, 0, sizeof(sh));
390 
391     /* make sure size and minsize are powers of 2 */
392     OPENSSL_assert(size > 0);
393     OPENSSL_assert((size & (size - 1)) == 0);
394     OPENSSL_assert(minsize > 0);
395     OPENSSL_assert((minsize & (minsize - 1)) == 0);
396     if (size <= 0 || (size & (size - 1)) != 0)
397         goto err;
398     if (minsize <= 0 || (minsize & (minsize - 1)) != 0)
399         goto err;
400 
401     while (minsize < (int)sizeof(SH_LIST))
402         minsize *= 2;
403 
404     sh.arena_size = size;
405     sh.minsize = minsize;
406     sh.bittable_size = (sh.arena_size / sh.minsize) * 2;
407 
408     /* Prevent allocations of size 0 later on */
409     if (sh.bittable_size >> 3 == 0)
410         goto err;
411 
412     sh.freelist_size = -1;
413     for (i = sh.bittable_size; i; i >>= 1)
414         sh.freelist_size++;
415 
416     sh.freelist = OPENSSL_zalloc(sh.freelist_size * sizeof(char *));
417     OPENSSL_assert(sh.freelist != NULL);
418     if (sh.freelist == NULL)
419         goto err;
420 
421     sh.bittable = OPENSSL_zalloc(sh.bittable_size >> 3);
422     OPENSSL_assert(sh.bittable != NULL);
423     if (sh.bittable == NULL)
424         goto err;
425 
426     sh.bitmalloc = OPENSSL_zalloc(sh.bittable_size >> 3);
427     OPENSSL_assert(sh.bitmalloc != NULL);
428     if (sh.bitmalloc == NULL)
429         goto err;
430 
431     /* Allocate space for heap, and two extra pages as guards */
432 #if defined(_SC_PAGE_SIZE) || defined (_SC_PAGESIZE)
433     {
434 # if defined(_SC_PAGE_SIZE)
435         long tmppgsize = sysconf(_SC_PAGE_SIZE);
436 # else
437         long tmppgsize = sysconf(_SC_PAGESIZE);
438 # endif
439         if (tmppgsize < 1)
440             pgsize = PAGE_SIZE;
441         else
442             pgsize = (size_t)tmppgsize;
443     }
444 #else
445     pgsize = PAGE_SIZE;
446 #endif
447     sh.map_size = pgsize + sh.arena_size + pgsize;
448     if (1) {
449 #ifdef MAP_ANON
450         sh.map_result = mmap(NULL, sh.map_size,
451                              PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE|MAP_CONCEAL, -1, 0);
452     } else {
453 #endif
454         int fd;
455 
456         sh.map_result = MAP_FAILED;
457         if ((fd = open("/dev/zero", O_RDWR)) >= 0) {
458             sh.map_result = mmap(NULL, sh.map_size,
459                                  PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
460             close(fd);
461         }
462     }
463     if (sh.map_result == MAP_FAILED)
464         goto err;
465     sh.arena = (char *)(sh.map_result + pgsize);
466     sh_setbit(sh.arena, 0, sh.bittable);
467     sh_add_to_list(&sh.freelist[0], sh.arena);
468 
469     /* Now try to add guard pages and lock into memory. */
470     ret = 1;
471 
472     /* Starting guard is already aligned from mmap. */
473     if (mprotect(sh.map_result, pgsize, PROT_NONE) < 0)
474         ret = 2;
475 
476     /* Ending guard page - need to round up to page boundary */
477     aligned = (pgsize + sh.arena_size + (pgsize - 1)) & ~(pgsize - 1);
478     if (mprotect(sh.map_result + aligned, pgsize, PROT_NONE) < 0)
479         ret = 2;
480 
481 #if defined(OPENSSL_SYS_LINUX) && defined(MLOCK_ONFAULT) && defined(SYS_mlock2)
482     if (syscall(SYS_mlock2, sh.arena, sh.arena_size, MLOCK_ONFAULT) < 0) {
483         if (errno == ENOSYS) {
484             if (mlock(sh.arena, sh.arena_size) < 0)
485                 ret = 2;
486         } else {
487             ret = 2;
488         }
489     }
490 #else
491     if (mlock(sh.arena, sh.arena_size) < 0)
492         ret = 2;
493 #endif
494 #ifdef MADV_DONTDUMP
495     if (madvise(sh.arena, sh.arena_size, MADV_DONTDUMP) < 0)
496         ret = 2;
497 #endif
498 
499     return ret;
500 
501  err:
502     sh_done();
503     return 0;
504 }
505 
sh_done(void)506 static void sh_done(void)
507 {
508     OPENSSL_free(sh.freelist);
509     OPENSSL_free(sh.bittable);
510     OPENSSL_free(sh.bitmalloc);
511     if (sh.map_result != MAP_FAILED && sh.map_size)
512         munmap(sh.map_result, sh.map_size);
513     memset(&sh, 0, sizeof(sh));
514 }
515 
sh_allocated(const char * ptr)516 static int sh_allocated(const char *ptr)
517 {
518     return WITHIN_ARENA(ptr) ? 1 : 0;
519 }
520 
sh_find_my_buddy(char * ptr,int list)521 static char *sh_find_my_buddy(char *ptr, int list)
522 {
523     size_t bit;
524     char *chunk = NULL;
525 
526     bit = (ONE << list) + (ptr - sh.arena) / (sh.arena_size >> list);
527     bit ^= 1;
528 
529     if (TESTBIT(sh.bittable, bit) && !TESTBIT(sh.bitmalloc, bit))
530         chunk = sh.arena + ((bit & ((ONE << list) - 1)) * (sh.arena_size >> list));
531 
532     return chunk;
533 }
534 
sh_malloc(size_t size)535 static void *sh_malloc(size_t size)
536 {
537     ossl_ssize_t list, slist;
538     size_t i;
539     char *chunk;
540 
541     if (size > sh.arena_size)
542         return NULL;
543 
544     list = sh.freelist_size - 1;
545     for (i = sh.minsize; i < size; i <<= 1)
546         list--;
547     if (list < 0)
548         return NULL;
549 
550     /* try to find a larger entry to split */
551     for (slist = list; slist >= 0; slist--)
552         if (sh.freelist[slist] != NULL)
553             break;
554     if (slist < 0)
555         return NULL;
556 
557     /* split larger entry */
558     while (slist != list) {
559         char *temp = sh.freelist[slist];
560 
561         /* remove from bigger list */
562         OPENSSL_assert(!sh_testbit(temp, slist, sh.bitmalloc));
563         sh_clearbit(temp, slist, sh.bittable);
564         sh_remove_from_list(temp);
565         OPENSSL_assert(temp != sh.freelist[slist]);
566 
567         /* done with bigger list */
568         slist++;
569 
570         /* add to smaller list */
571         OPENSSL_assert(!sh_testbit(temp, slist, sh.bitmalloc));
572         sh_setbit(temp, slist, sh.bittable);
573         sh_add_to_list(&sh.freelist[slist], temp);
574         OPENSSL_assert(sh.freelist[slist] == temp);
575 
576         /* split in 2 */
577         temp += sh.arena_size >> slist;
578         OPENSSL_assert(!sh_testbit(temp, slist, sh.bitmalloc));
579         sh_setbit(temp, slist, sh.bittable);
580         sh_add_to_list(&sh.freelist[slist], temp);
581         OPENSSL_assert(sh.freelist[slist] == temp);
582 
583         OPENSSL_assert(temp-(sh.arena_size >> slist) == sh_find_my_buddy(temp, slist));
584     }
585 
586     /* peel off memory to hand back */
587     chunk = sh.freelist[list];
588     OPENSSL_assert(sh_testbit(chunk, list, sh.bittable));
589     sh_setbit(chunk, list, sh.bitmalloc);
590     sh_remove_from_list(chunk);
591 
592     OPENSSL_assert(WITHIN_ARENA(chunk));
593 
594     /* zero the free list header as a precaution against information leakage */
595     memset(chunk, 0, sizeof(SH_LIST));
596 
597     return chunk;
598 }
599 
sh_free(void * ptr)600 static void sh_free(void *ptr)
601 {
602     size_t list;
603     void *buddy;
604 
605     if (ptr == NULL)
606         return;
607     OPENSSL_assert(WITHIN_ARENA(ptr));
608     if (!WITHIN_ARENA(ptr))
609         return;
610 
611     list = sh_getlist(ptr);
612     OPENSSL_assert(sh_testbit(ptr, list, sh.bittable));
613     sh_clearbit(ptr, list, sh.bitmalloc);
614     sh_add_to_list(&sh.freelist[list], ptr);
615 
616     /* Try to coalesce two adjacent free areas. */
617     while ((buddy = sh_find_my_buddy(ptr, list)) != NULL) {
618         OPENSSL_assert(ptr == sh_find_my_buddy(buddy, list));
619         OPENSSL_assert(ptr != NULL);
620         OPENSSL_assert(!sh_testbit(ptr, list, sh.bitmalloc));
621         sh_clearbit(ptr, list, sh.bittable);
622         sh_remove_from_list(ptr);
623         OPENSSL_assert(!sh_testbit(ptr, list, sh.bitmalloc));
624         sh_clearbit(buddy, list, sh.bittable);
625         sh_remove_from_list(buddy);
626 
627         list--;
628 
629         /* Zero the higher addressed block's free list pointers */
630         memset(ptr > buddy ? ptr : buddy, 0, sizeof(SH_LIST));
631         if (ptr > buddy)
632             ptr = buddy;
633 
634         OPENSSL_assert(!sh_testbit(ptr, list, sh.bitmalloc));
635         sh_setbit(ptr, list, sh.bittable);
636         sh_add_to_list(&sh.freelist[list], ptr);
637         OPENSSL_assert(sh.freelist[list] == ptr);
638     }
639 }
640 
sh_actual_size(char * ptr)641 static size_t sh_actual_size(char *ptr)
642 {
643     int list;
644 
645     OPENSSL_assert(WITHIN_ARENA(ptr));
646     if (!WITHIN_ARENA(ptr))
647         return 0;
648     list = sh_getlist(ptr);
649     OPENSSL_assert(sh_testbit(ptr, list, sh.bittable));
650     return sh.arena_size / (ONE << list);
651 }
652 #endif /* OPENSSL_SECURE_MEMORY */
653